In the Gundam anime series, the One-Year War is the first major war of the Universal Century (UC) and is setting of many stories in the series. The One-Year War is analogous to World War II, with the war being between the Earth Federation and the Principality of Zeon, with only very few neutral factions on the sidelines. The analogy is made more clear in later renditions of events during the war, specifically those shown in Gundam 0080 and Gundam 0083, with the 'nazification' of the Zeons.
The One-Year War begins on January 3rd of 0079 of the UC calendar and technically ends on January 14th, UC0080, although hostilites end on January 1st of the same year.
The One-Week War culminated in Operation British, supposedly named after the American Revolution against British rule in the 1770s. Operation British's goal was to destroy the Federation's nuke-hardened military central command at Jaburo, using a recently depopulated colony cylinder. If the plan succeeded, the Zeons would have been able to force the Earth Federation to their aceed demands and shorten the war. The Federation's space forces mobilized as the Zeon set the colony on a slingshot course around the moon. However, the colony falls short. It began to break up over the Indian ocean, but a massive piece, the 30km cylinder itself, fell on the heavily-populated city of Sydney, Australia. A 60,000 Megaton blast causes a 500-kilometer crater, destroying 16% of the continent and causing massive climate changes.
The Battle of Loum is signature in Gundam as it makes many of the series' famous aces. Char Aznable sinks five of the Federation's top of the line Magellan battleships and earns his nickname the 'Red Comet', while the 'Black Tri-Stars' capture General Reville, the highest ranking General in the Federation. However, many of the original mobile suit training cadres are killed, leaving very few trainers. This causes problems with the quality of training in Zeons pilots later in the war.
A second drop operation occurs in North America, with two divisions being dropped on both coasts and moving inward. One division captures the strategically important California Base, a series of a massive manufacturing plants and ports along the West Coast. Along with this, much of the Earth Federation's naval fleet is captured and is later pressed into service under the Zeon flag.
A third drop is directed at the destablized region of Australia, southeast Asia, and Oceania.
The fourth drop operation is commenced on April 4th, and lands on the Red Sea and in the Persian Gulf.
For the next five months, the lines expand and then solidify in a stalemate. At this point, the Zeons have control of over two-thirds of the Earth's landmass.
Another first in the Universal Century is the first ever mobile suit atmospheric re-entry, which is also completed by Amuro Ray and the Gundam, on September 18th. While being pursued by Char Aznable, the White Base re-enters Earth's atmosphere, but is knocked off it's projected course to Jaburo and instead lands in enemy territory in North America.
Public-class assault boats neutralize the space fortress' beam cannon defenses with beam-dispersing smoke clouds, allowing the Federation's warships to close range. The Federation also unleashes a secret weapon: a solar reflector array, known as the Solar System, that cooked any mobile suit or ship that tried to exit Solomon.
With casualties mounting and reinforcements being held back due to sibling rivalry, Space Attack Forces and Solomon commander Dozle Zabi orders the evacuation of the base and boards the mobile armor known as Byg-Zam. While the Byg-Zam inflicts significant losses on the assaulting Federation fleet and allows many of the Zeons to retreat from the base, it's Dozle Zabi's pyrrihic victory. Dozle Zabi is soon killed in action by Amuro Ray. Solomon is soon afterwards captured by the EFF and renamed Konpei.
As the construction of the Solar Ray System was being completed and the Federation fleet drew near, Degwin Zabi left on a secret mission to save what was left of the Principality of Zeon. He was to meet with General Reville at Geldolva line and negotiate the terms of surrender. His departure was not unnoticed by Gihren Zabi, who quickly rushed the Solar Ray System into operation, so much so that the Solar Ray would only be able to be fired once. As this was happening, General Reville organized the main Federation fleet into three battlelines. At 2035GMT, Gihren Zabi gave the order to all Zeonic fleets to pull out of the firing range in front of the Solar Ray System. As this was happening, Degwin Zabi and General Reville met to discuss a peace treaty to end the war. At 2105GMT, Gihren Zabi order the Solar Ray System to be fired at the Geldolva aiming point. General Reville, Degwin Zabi, and about a third of the Federation's fleet were wiped out in the blast. The IR band signature from the Solar Ray System's discharge is detected by Mobile Assault Force commander Kycillia Zabi's fleet, traveling to reinforce the Zeon's last line of defense. Origins of the One-Year War
The One-Week War
The opening to the One-Year War was originally refered to as the One-Week War.
The Zeons launch a surprise attack against the Federation's garrisons at the space colonies located in the Zahn province of Side 1 (Lagrangian point 5), Hatte Province in Side 2 (L4) and Mua Province in Side 4 (L5). Nuclear weapons are used indiscrimately, while the Zeons' nerve gas used to suppress the garrisons from mobilizing kills the civilians they are supposed to protect. Over 2.8 billion people are killed during one day of fighting.The Battle of Loum
After the failure of Operation British, the Zeons launch an attack on Loum province in Side 5 (L1) on Januray 15th, UC0079, in an second attempt to drop a colony cylinder on Jaburo. However, the operation is intercepted by the Earth Federation Forces and Dozle Zabi, commander of the Space Attack Force, presses his Zaku Mobile Suits into action against the Federation fleet. The resulting battle destroys many of the space colonies and their inhabitants, resulting in over 2.5 billion dead. Another 500 million combatants are killed in action.The Antarctic Treaty
With the capture of General Reville, the aborted colony drop and heavy losses on both sides, the Federation and Principality of Zeon agree to a truce. While negotiating a conditions of surrender, and clearly in favor of the Principality of Zeon, General Reville escapes from Zeon and makes a speech revealing that 'Zeon is exhausted!' to the Federation Assembly. The Federation rejects the conditions of surrender, but agrees to a treaty prohibiting the use of nuclear, biological, and chemical weapons and colony drops, recognizing the sanctity of the neutral space colonies of Side 6 (L4) and the moon, and determining the rules of war. The Antarctic Treaty is signed on January 31st, UC0079.The Earth Attack Drop Operations
With the signing of the Antarctic Treaty, the prohibition of nuclear weapons, biological/chemical weapons, and colony drops dashes the Zeons hope for a quick conclusion to the war. The Zeons begin mobilizing for it's invasion of Earth. A new unit, the Earth Attack Force, is formed and stages it's first drop operation on March 1st, UC0079. The drop operation quickly captures the EFF's Baiknor launch facilities and then move onto the resource center of Odessa.The White Demon Rises
On September 18th, an incident occurs that quite possibly changes the entire course of the war, in a space colony located at Side 7 (L3). While transferring the components of a Federation secret project under the guise of a supply run and spacelifting civilians, members of a Zeon Zaku recon team, break orders and begin attacking the colony. In the confusion, civilian Amuro Ray comes across the result of the secret project, the Gundam. Unaccustomed to battle, but possessing a high degree of technical aptitude, Amuro manages to get the Gundam off it's trailer and manages to destroy two of the Zaku recon team. This is the first ever mobile suit battle inside a space colony in the UC timeline. Unfortunately, the result leaves the colony heavily damaged, Amuro's father, the 'V' Project's team leader Temu Ray, missing, and many civilians dead and the surivors as refugees aboard the White Base.Operation Odessa
The Earth Federation amasses one third of it's terrestrial forces along eastern Europe for possibly one of the largest land battles in the UC history. Operation Odessa's aim is to recapture the Odessa mining facility and break the Zeon hold on resources. The campaign began on November 7th. Over the next two days, the Federal Forces stage a blitzkrieg attack on the Zeon's defensive lines, breaking through and overwhelming them. On November 9th, the Federal Forces break through the last of the Zeon Occupation Force's defensive lines, triggering an ultimatum from Colonel M'Quve. M'Quve demands that the Federal Forces withdraw or else he will be forced to use nuclear weapon, in violation of the Antarctic Treaty. It is said that General Reville signalled to his communications officers not to respond. Fleeing the battlefield in the Zanzibar-class mobile cruiser Madagascar, M'Quve launched a single nuclear missile, but was destroyed by Amuro Ray in the Gundam. The battle ground to a close, with many of the Zeon's forces Europe and Asia thown into disarray.Operation Rainbow Valley
Exploiting the discord with the Zeon forces after the fall of Odessa, the Federation begins Operation Rainbow Valley, with the objective of recapturing Australia on November 23rd. The operation is spearheaded by Master P. Rayer and his the 'White Dingo' team. The team captures Alice Springs on November 25th, Simpson's Gap on December 1st, repulses a Zeon counterattack at the EFF base at Torrington on December 26th, and captures one of the last remaining Zeon Heavy Lift facilities at Hughenden on January 2nd, 0080.Operation Velvet
Following the completion of Operation Odessa, the Federation launches an offensive into Lepanto region of North Africa. The campaign began on November 18th and completes it's objectives on November 28th.The Jaburo Drop Operation
After a spy managed to infiltrate the White Base, Char Aznable discovers the location of the Earth Federation's fortress of Jaburo. On November 30th, after gathering mobile suit squads from California Base and with massive air and naval support, he launches an assault on Jaburo. Amphibious mobile suit and commando teams lead by Char himself make numerous probes and raids into the heart of the base, but fails to take the base nor destroy the mobile suit factory. The Jaburo attack fails and the Zeons retreat on the same day. The combined losses at Odessa and Jaburo break the Zeon Earth-bound armies, making it easy for the Federation to begin launching offensives against other holdings in Africa and North America. Over the month of December, the Zeon forces are in full retreat, abandoning bases and trying to escape into space. The Cape Canaveral base is liberated on December 5th, at a cost 34 fighters, 71 tanks, and 2 mobile suits, due to the ace pilot Thomas Greydon. The California Base is recaptured on December 11th.Operation Rubicon
This is a secret Zeon commando operation performed by Hardy Steiner's Cyclops Commandos. The mission was to destroy a prototype Gundam designed for Newtypes. The mission is detailed in the OVA series Gundam 0080.Operation Star One
With the battle on Earth grinding to a close, the Federation began to plot to retake space. The high command's plan has two parts:
Battle of Solomon
After distracting the Zeons' attention with a battle outside of the neutral space of Side 6, in which Amuro Ray and the Gundam destroyed 12 of the latest frontline mobile suit named the Rick Dom in the span of a single minute, the White Base rendezvous with the Federation fleet to assault the Zeon space fortress Solomon, on December 24th. The battle is the first in which the GM, or Gundam Mass-production, is used in mass. The GM had only seen limited, squad-level engagements during it's test phase and on Earth prior to Solomon. Operation Solar Ray
Following the loss of Odessa and Solomon, the Zeon military was on the defensive. Fearing the Federation's next move would be a full-scale assault on the home colonies, Zeon's Supreme Commander Gihren Zabi ordered the construction of a massive solar powered beam projector known as the Solar Ray System. The project was originally started in the Mahal colony in September, to exploit the same loophole in the Antarctic Treaty that the Federation's Solar System had done. Supervised by Colonel Asakura, who also developed Zeon's 3G nerve gas, solar batteries from other colonies were collected and a projection array built within the colony walls, and, on December 21st, it's 6.5 million inhabitants were order to evacuated, although this was completed four days behind schedule.